ath9k_hw: sync initvals for ar9001 and ar9002 with Atheros

This includes the following changes/fixes:

 - a bugfix for stuck beacon issues
 - timing changes for improved performance
 - AGC setting improvements
 - fixes for high temperature issues on some chips

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>